notes with (detective conan) can increase your interest..... it's not just study but we should care about our earth!! 'Save Our Earth'

3. Control the use of fertilisers by:
Applying only when crops are growing
Not applying in empty fields
Not spraying when there is a forecast of rain
Not disposing of them into rivers and ponds
Reducing the usage of excess nitrates from fertilisers and
ammonia

5. Suspended solids
-Reduced light penetration
- if suspended solids are biodegradable, they can be decomposed by
microorganisms and this process requires a high demand for oxygen
Treats sewage before it enters rivers
Prevent farm slurry (liquid manure) from entering rivers and
ponds
Nitrates and phosphates
- Lead to eutrophication

6. Detergents
- ‘hard’ detergents create foam which reduces the supply of
oxygen to organisms living in water
- ‘soft’ detergents are biodegradable but may contain high levels
of phosphates which can lead to eutrophication
Use biodegradable detergents with low phosphate
content

7. Microorganisms such as bacteria and protozoa
- If the water is used for drinking, it must be properly
treated or it may cause water-borne diseases such as
cholera
Drink properly treated and boiled water

8. Effluents from industries
Heavy metals such as copper, mercury, zinc and chromium
- Highly toxic and accumulate in the organisms via food chains
- Mercury can cause acute nervous disorders in humans
Oil, grease and suspended solids
Waste water contains numerous contaminants, including
hydrogen sulphide
Treat effluents before they are
discharged into water sources
Take illegal action against illegal
dumping of toxic wastes

9. Underground pipes
Lead
- Lead is a highly toxic heavy metal which can
accumulate in the tissues of living organisms
- Lead can impair the mental ability of children
Use copper pipes instead of lead pipes
in plumbing

12. Biochemical oxygen demand or B.O.D. is the amount of dissolved
oxygen needed by aerobic biological organisms in a body of water
to break down organic material present in a given water sample at
certain temperature over a specific time period. The term also
refers to a chemical procedure for determining this amount. This is
not a precise quantitative test, although it is widely used as an
indication of the organic quality of water.[1] The BOD value is most
commonly expressed in milligrams of oxygen consumed per litre of
sample during 5 days of incubation at 20 °C and is often used as a
robust surrogate of the degree of organic pollution of water.
BOD can be used as a gauge of the effectiveness of wastewater
treatment plants. It is listed as a conventional pollutant in the
U.S. Clean Water Act.

13. THE PROCESS AND CONSEQUENCES OF
EUTROPHICATION

15. Thermal pollution

17. Ways to prevent
- Control the amount of hot water discharged
from industrial plants and power stations
into the surrounding lakes and rivers
- Control the amount of hot water or
industrial effluents discharged into still or
slow moving rivers

18. Noise pollution
- Noise from cars, motorcycles, aeroplanes, construction sites, agricultural and
industrial machinery can be a form of pollution
- The noise level of residential areas should not exceed 55 decibels (dB)
- According to the World Health Organization (WHO), prolonged exposure to
noise levels at or above 80 decibels (dB) can lead to deafness
- Excessive exposure to high levels of noise is considered a health risk because
noise can contribute to stress-related problems such as high blood pressure,
coronary disease, ulcers, depression and headaches
- Loud noise can cause an arousal response in which a series of reactions occurs
in the body. Adrenaline is released into the blood stream. A person's heartbeat
rate , blood pressure and respiration rate are likely to increase. The blood
vessels constrict and the muscles become tense
- It is possible that repetitive or constant exposure to noise can be harmful to
health

19. Question?